Final answer:
Bond length ranking from longest to shortest among N-I, N-H, and N-O bonds is N-I > N-H > N-O, with the N-I bond being the longest due to the larger size of iodine, followed by the N-H bond, and finally the N-O bond which is typically a multiple bond and thus shorter.
Step-by-step explanation:
When ranking the bonds according to length from longest to shortest (N-I, N-H, N-O), we must consider factors such as the size of the bonded atoms and the bond order.
Generally, larger atoms form longer bonds, and multiple bonds are shorter than single bonds. Nitrogen (N) is smaller than iodine (I), but larger than hydrogen (H) and oxygen (O).
Therefore, we would expect the N-I bond to be the longest since iodine is the largest atom of the group. The N-H bond should be shorter than the N-I bond due to hydrogen's small size.
Lastly, the N-O bond is typically involved in a double or triple bond context (for example in the NO3− ion the bond order is around 1.33), making it shorter than a typical N-H single bond.
Thus, the correct ranking from longest to shortest bond lengths is N-I > N-H > N-O.